Ventilation baffle

ABSTRACT

Temperature equalizing means for roofs. Means are provided for containing and controlling ceiling insulation so as to provide adequate air-flow communication between a first zone defined between the ceiling and the roof of a building and a second zone defined between projecting eaves of said building and soffits immediately thereunder. Such communication maintains the roof at a more nearly uniform temperature across the entire width of the roof so that during cold weather melting of snow on the roof is minimized and thereby the build-up of a ridge of ice along the eaves caused by freezing of melted snow is minimized and, consequently, leakage of melted ice under the shingles and through said roof is prevented. The device comprises a channel-shaped member positionable between the rafters of the building and spaced from the inside surface of the roof boards whereby communication between said first and second zones is not blocked by the installation of insulation on said ceiling.

FIELD OF THE INVENTION

The invention relates to means for preventing the buildup of ice alongthe eaves of a building and thereby preventing resultant leakage ofmelted ice under the shingles and through the roof of such building. Theinvention comprises particularly means for maintaining a channel ofair-flow communication between a first zone immediately under such roofand a second zone between the eaves and the soffit associated therewith.

BACKGROUND OF THE INVENTION

In conventional frame building construction, there is frequentlyprovided a soffit which extends substantially horizontally from theouter wall of such building to the outer edges of its eaves. There isalso normally provided between the lower surface of the roof of suchbuilding and the upper edge of the wall thereof passages between theroof rafters which provide communication between a first zoneimmediately under the roof thereof and a second zone defined between theprojecting eaves and the soffit. This communication permits at least asmall amount of outside air to move into the zone between the eaves andthe soffit and to move from that zone into the zone under the roof.Also, there is or are provided one or more ventilating openings near thepeak of the roof for allowing relatively warm air to escape. Thus, incold weather, relatively warm air that rises toward the peak of the roofcan become mixed with cooler outside air that flows through thepassages, thereby to maintain a more uniform cooler temperature acrossthe entire width of the roof. However, when the buiding is insulated byplacing a layer of insulation on top of the ceiling of whatever livingspace is provided below the zone immediately under such roof, theseopenings are often blocked and outside air is no longer permitted toflow from the zone between the eaves and soffit into the zone directlyunder the roof. Thus, in cold weather, because room heat that flowsupwardly through the insulation tends to accumulate toward the peak ofthe roof, melting of snow will occur thereat, such melted snow will flowdown along the roof and will often freeze as it reaches the outer edgeof the eaves which are unheated. Consequently a ridge of ice builds upalong the eaves and as subsequent melting occurs, the thawed ice on theeaves often flows back under the shingles of said roof and causesleakage through the ceiling above mentioned and/or into the inside ofthe building wall.

This problem is well known and has long been recognized and numerousdevices have been provided in an attempt to correct same. Oneparticularly common means for accomplishing this purpose is to provide aresistance heating wire along the edge of said eaves, or a resistancewire describing a circuitous pattern immediately back from the edge ofsuch eaves, in order to prevent the formation of ice thereon. Thissystem works well but it is both expensive to install and requires theconstant use during cold weather of a substantial amount of electricalenergy.

Other means have also been provided but insofar as I am aware, they haveall either been even more expensive to install and/or operate than theresistance wire means above-mentioned or they have been insufficientlyeffective to be satisfactory.

Accordingly, the objects of the invention include:

1. To provide means for preventing insulation installed above a ceilingfrom blocking air flow between a first zone under said roof and a secondzone between the projecting eaves of such building and a soffitassociated therewith, so that cool outside air can flow into said firstzone to maintain the roof at a more uniform cooler temperature acrossits entire width in order to minimize melting of snow thereon.

2. To provide means, as aforesaid, for maintaining a channel of air flowcommunication past insulation between said first zone and said secondzone.

3. To provide inexpensive means, as aforesaid, which may be installedbetween roof rafters during the application of ceiling insulation forpreventing such insulation from blocking air flow communication betweensaid first and second zones but instead insuring a continuous channel ofair flow communication therebetween.

4. To provide a device, as aforesaid, which will be sufficientlyinexpensive as not to add materially to the cost of the insulation job.

5. To provide a device, as aforesaid, which can be installed readily andquickly by simple means and at the same time as the insulation and willthereby not add materially if at all to the labor cost of an insulationjob.

6. To provide a device, as aforesaid which will easily last as long asthe insulation and/or the building and hence not require repair orrenewal during the normal life of either the insulation or of thebuilding.

7. To provide a device, as aforesaid, wherein the manner of installationcan be readily explained to workmen installing such insulation and whichwill not require special equipment or tools for the installation of suchdevice.

8. To provide a device, as aforesaid, which can be installed as requiredby means of the same tools as utilized for installing the insulation.

Other purposes and objects of the invention will be apparent to personsacquainted with devices of this general type upon reading the followingspecification and inspection of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a top view of a blank from which may be formed the device ofthe invention.

FIG. 2 is a vertical sectional view through a roof, wall and ceilingshowing the device of the invention installed into position.

FIG. 3 is a sectional fragmentary view taken on the line III--III ofFIG. 2.

FIG. 4 is a sectional view taken on the line IV--IV of FIG. 2.

DETAILED DESCRIPTION

Referring now to the drawings, there is shown in FIG. 2 a conventionalwall structure 1 having in this illustration a conventional upper plate2, an outer wall panel 3 and an inner wall panel 4. Above said walls,there is provided a conventional ceiling 6 comprising the usualplurality of parallel rafters of which two appear at 7 and 8 togetherwith a single or multilayer bottom panel 9 comprising the ceiling of theliving space 11.

Positioned above such ceiling structure 6 is a conventionallyconstructed roof 12, here comprising a plurality of parallel rafters ofwhich two appear at 13 and 14 and a roof panel 16 which may be single ormulti-layer as desired. Said roof panel is then covered by conventionalshingles 17 in the usual manner, which shingles may be wood orcomposition of any ordinary nature or type without changing theapplicability of the invention. The eaves indicated at 18 project beyondthe building wall 1 in a normal manner; a facia 19 extends downwardlyfrom the outer edge of the roof panel 16 and a soffit 21 extends fromthe facia 19 to the outer wall panel 3 to close the space therebetween.

The foregoing describes the usual frame construction of a roof andceiling construction immediately above an outer wall of a framebuilding. In the absence of insulation, the zone above the plate 2 andbetween the rafters, such as between the rafters 13 and 14, provides forsufficient communication between a first zone 22 between the roof 12 andthe ceiling 6 and a second zone 23 between the eaves 18 and the soffit21 as to insure that outside air can flow into second zone 23 and thenceinto zone 22 to mix with relatively heated air therein and maintain theinternal surface of the roof 12 at a more uniform, relatively coolertemperature across its entire width. Thus, the inner and outer surfacesof the roof are at more nearly equal temperatures which is effective tominimize melting of the lower surface of the layer of snow on the roofcaused by room heat from the building. This, in turn, minimizes build-upof ice dams on the eaves caused by freezing of melted snow when it flowsabove the eaves.

However, when insulation, such as the insulation I is installed abovethe ceiling 6 and between the joists such as the rafters 7 and 8thereof, such insulation will often block such communication zones andprevent the outside air flow from the second zone 23 into the first zone22. Thus, heat escaping from the upper surface of the insulation I flowsupwardly to contact and heat the inner surface of the roof. Underappropriate weather conditions and snow loads, this heat will melt thelower surface of the snow adjacent the roof surface, the water will flowdown to the eaves and will be frozen thereat so that a ridge of ice willbuild up on the outer edge of the eaves.

All of the foregoing is well-known and is set forth in detail only toset forth clearly the environment in which the invention is used andinsure an understanding of its manner of operation.

Turning now to the means comprising the invention, there is provided aretainer member 31 for installation between the rafters such as betweenthe rafters 13 and 14 as shown best in FIG. 4. This retainer member isfixed between said rafters, as aforesaid, prevents the movement of theinsulation I into position closing the zone between said rafters andhence prevents the blocking of communication between the first zone 22and the second zone 23. Alternatively stated, the retainer 31 maintainsa passageway 32 to insure continued communication from said first zone22 to the second zone 23.

While said retainer 31 may be formed in any of several specific ways,one preferred way is indicated by FIG. 1 which illustrates a blank Bfrom which a suitable such retainer may be formed. Said blank B isprovided with fold lines as indicated by the dotted lines in FIG. 1 andis provided with cuts as indicated by the solid lines 33-38 in FIG. 1.

Folding of said blank B on the dotted lines 39 and 41 forms a retainerhaving a bottom member 42 and upwardly extending sides 43 and 44.Folding on the fold line 46 provides a downwardly extending end wall 47and stapling or otherwise fastening of the tabs 48 and 49 effectsstiffening of the structure. However, the stiffening structurerepresented by the end wall 47 and the tabs 48 and 49 may be eliminated,if desired, to reduce the expense of the device and same will stillfunction effectively.

Folding on the fold line 51, and folding on the fold lines 52 and 53 ifsame have not already been folded, provides a downwardly extending endwall 54 and upright tabs 56 and 57. Said tabs 56 and 57 projectdownwardly as shown in FIG. 2 and provide for the support of theretainer member 31 on the upper surface of the upper plate 2. They alsoproject upwardly substantially into abutment with the roof deck 16.

With the parts folded as above described, same may be fixed into thebox-shape thus provided in any convenient manner, such as by gluing orstapling. Said retainer member is then positioned between a pair ofrafters with its bottom member 42 sufficiently spaced downwardly fromthe roof panel 16 as to provide the passageway 32 and said retainermember may then be fastened to said rafters in any convenient manner,such as by stapling. The space between as many pairs of rafters asdesired may be provided with retainer members in the manner abovedescribed according to the amount of communication it is desired tomaintain between the first and second zones 22 and 23. However, it willnormally be preferred to have a retainer member as described placedbetween each pair of rafters along the full length of each side of thebuilding concerned in order that this communication may be maintained ata maximum level and the tendency for ice to form along the outer edgesof the eaves will be minimized.

The retainer member may be made of any desired sheet material but aninexpensive corrugated paper board will be effective in all usualsituations.

In use, outside air under positive air pressure, such as caused byatmospheric wind, will enter through openings in soffit 27 into the zone23. The outside air will then flow through passages 32 along theunderside of the roof deck 16 into the zone 22. The flow of air keepsthe roof deck 16 at a temperature as close as possible to the outsidetemperature and thus minimizes melting of the bottom surface layer ofany snow that is present on the roof.

By bending flange 54 and flanges 43 and 41, as needed, about theirrespective fold lines 51, 39 and 41, variations in rafter spacing androof pitch can be accommodated. Further, because the lower edge offlange 57 rests on upper plate 2, said flange and thus the rest of theretainer member 31 cannot be pushed outwardly. Thus, the retainer memberis self-adjusting and self-locking in position.

The national interest in saving energy is critical. Every means ormaintaining or increasing the efficiency of household heating to cutdown energy consumption must be utilized.

The extension of the usable life of a home without expensive repairs isalso in the national interest.

This invention will contribute to both these objectives by helping toeliminate moisture in the attic space. It keeps the insulation dry andmuch more efficient in saving fuel. By helping to eliminate ice damsalong roof eaves it extends the life of the building with fewerexpensive repairs.

This invention assures adequate ventilation space between the insulationand the roof deck at the juncture where attic space joins the space inthe overhang of the roof structure. It is unique in that while insuringproper ventilation it gives 100% closure below the ventilation space tokeep insulation particles from falling or blowing into the overhangspace and thereby prevents clogging of the flat screened openings in thesoffit panels. It is also unique in that the design allows for automaticadjustment to any roof pitch. It is unique in that variance of spacingbetween roof rafters can be easily accommodated.

Although a particular preferred embodiment of the invention has beendisclosed in detail for illustrative purposes, it will be recognizedthat variations or modifications of the disclosed apparatus, includingthe rearrangement of parts, lie within the scope of the presentinvention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. An insulation stop andventilation baffle for minimizing ice accumulation on the eaves of aceiling-insulated building wherein the building comprises upstandingwalls having a horizontal top plate, horizontal ceiling joists having aceiling affixed to the undersides thereof, roof rafters inclinedupwardly from said ceiling joists and having roof sheathing affixed tothe tops of said roof rafters, the space between said ceiling and saidroof sheathing defining an attic, said ceiling joists and said roofrafters extending to said top plate and being affixed thereto, said roofrafters extending outwardly beyond said top plate to form eaves so thatthe attic and the eaves communicate by means of openings defined betweenadjacent roof rafters, said baffle comprising an elongated generallyrectangular retainer member of stiff material, said retainer memberhaving a pair of longitudially extending, parallel, fold linesrespectively located close to the opposite lateral edges of saidretainer member to divide said retainer member into a rectangularcentral portion and a pair of rectangular lateral edge portions onopposite sides of said central portion so that said lateral edgeportions of said retainer member can be bent upwardly relative to saidcentral portion to form upstanding sides positionable adjacent theopposing surfaces of a pair of adjacent roof rafters and extendingsubstantially into contact with the lower surface of said roof sheathingwhereby to position said central portion substantially parallel with andspaced a fixed distance downwardly from the lower surface of said roofsheathing thereby to define an air-flow passageway which is open at bothits ends, said retainer member having an outer transversely extendingfold line located close to the outer longitudinal end of said retainermember and defining an outer rectangular end portion so that said outerend portion can be positioned at the juncture of said roof rafters andceiling joists above said top plate and can be bent downwardly relativeto said central portion to define an outer downwardly extending end wallbetween the opposing surfaces of a pair of adjacent roof rafters andextending downwardly from said central portion substantially intocontact with said top plate, a pair of rectangular outer tabs formed atthe outer ends of said lateral edge portions of said retainer memberadjacent said outer rectangular end portion, each of said outer tabsbeing defined by an outer transversely extending cut line spacedlongitudinally inwardly from said outer transversely extending fold lineand extending between the adjacent longitudinal edge of said retainermember and the adjacent longitudinally extending fold line, alongitudinally extending cut line extending longitudinally from theinner end of said outer transversely extending cut line to said outertransversely extending fold line and an outer tab fold line extendinglongitudinally from said outer transversely extending fold line to theadjacent outer end edge of said retainer member, said longitudinallyextending cut line and said outer tab fold line being longitudinallyaligned with and constituting extensions of said longitudinallyextending fold line for said lateral edge portion so that said tabs canbe bent into upright positions wherein they extend between said topplate and the lower surface of said sheathing and substantially parallelwith said lateral edge portions.
 2. An insulation stop and ventilationbaffle as claimed in claim 1 including an inner transversely extendingfold line located close to the inner end of said retainer member anddefining an inner rectangular end portion which extends downwardly toform an inner downwardly extending end wall between the opposingsurfaces of a pair of adjacent roof rafters, a pair of rectangular innertabs formed at the inner ends of said lateral edge portions of saidretainer member adjacent said inner rectangular end portion, each ofsaid inner tabs being defined by an inner transversely extending cutline aligned with said inner transversely extending fold line andextending between the adjacent longitudinal edge of said retainer memberand the adjacent longitudinally extending fold line, an inner tab foldline extending longitudinally from said inner transversely extending cutline to the adjacent inner end edge of said retainer member, said innertab fold line being aligned with and constituting an extension of saidlongitudinally extending fold line for said lateral edge portion so thatsaid inner tabs can be bent downwardly parallel with said lateral edgeportions.